[ios] Adds authentication, popup_menu and side_swipe resources

ios/chrome/browser/ui/popup_menu/BUILD.gn

Index: ios/chrome/browser/ui/popup_menu/BUILD.gn
diff --git a/ios/chrome/browser/ui/popup_menu/BUILD.gn b/ios/chrome/browser/ui/popup_menu/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..7ac0c6771d9ced4d430a8f1d03b99fabf094552d
--- /dev/null
+++ b/ios/chrome/browser/ui/popup_menu/BUILD.gn
@@ -0,0 +1,14 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+bundle_data("resources") {
+  sources = [
+    "resources/popup_background.png",
+    "resources/popup_background@2x.png",
+    "resources/popup_background@3x.png",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/{{source_file_part}}",
+  ]
+}